Local interconnection arrangement with reduced junction leakage and method of forming same

Abstract

A method and arrangement for forming a local interconnect without etching completely through a junction and causing device shorts introduces an additional ion implantation step following the etching of the local interconnect opening into the substrate. The additional ion implantation step into the active region ensures that the depth of the junction is below the depth reached by the local interconnect opening and the substrate.

What is claimed is:  
     
       1. A method of forming a local interconnect, comprising the steps of: 
       implanting ions within a semiconductor substrate to form active regions within the substrate;  
       depositing a dielectric layer over the substrate;  
       etching the dielectric layer in accordance with a desired pattern to form a local interconnect opening;  
       forming a barrier layer within the local interconnect opening;  
       implanting additional ions through the barrier layer and within the semiconductor substrate to enlarge the active regions; and  
       depositing conductive material in the local interconnect opening.  
     
     
       2. The method of claim  1 , wherein the active region is enlarged such that the depth of the active region in the substrate is greater than the depth of the local interconnect opening etched in the substrate during the etching of the dielectric layer. 
     
     
       3. The method of claim  2 , wherein the step of implanting ions and the step of implanting additional ions include implanting at least one of boron or phosphorous ions. 
     
     
       4. The method of claim  2 , wherein the step of implanting ions includes implanting the ions with an energy between about 20 KeV and about 60 KeV. 
     
     
       5. The method of claim  4 , wherein the step of implanting additional ions includes implanting the additional ions with an energy between about 45 and about 120 KeV. 
     
     
       6. The method of claim  5 , wherein the depth of the enlarged active region is greater than about 200 Angstroms.